growth hormone secreting pituitary adenoma 2

Growth Hormone Secreting Pituitary Adenoma: A Rare but Serious Condition

A growth hormone-secreting pituitary adenoma, also known as a somatotroph adenoma, is a type of tumor that develops in the pituitary gland. This rare condition affects about 2 in 10 people with pituitary tumors and can cause various symptoms depending on age.

Symptoms in Adults

In adults, growth hormone-secreting pituitary adenomas are a common cause of acromegaly, a serious condition that results from too much growth hormone. Acromegaly can lead to:

• Changes in facial features, including larger lips, nose, and tongue
• Longer lower jaw and wide spaces between teeth
• Joint pain and increased sweating

Age-Related Symptoms

The symptoms of growth hormone-secreting pituitary adenomas vary depending on age. In children, these tumors can cause gigantism, a condition characterized by excessive growth before the fusion of bony epiphysis.

Prevalence and Histopathological Viewpoint

Growth hormone-secreting adenomas correspond to about 20% of all pituitary adenomas. From a histopathological viewpoint, various adenomas may present with clinical signs and symptoms of GH hypersecretion, including pure GH cell adenomas (densely and sparsely granulated GH adenomas).

References

• [1] Growth hormone–secreting pituitary adenomas begin in the somatotropic cells of the pituitary gland.
• [2] Somatotroph adenomas make excess growth hormone and cause different symptoms depending on age.
• [5] The majority of patients with acromegaly harbor a functioning growth hormone (GH) pituitary adenoma.
• [10] Pituitary tumors that make growth hormone also are called growth hormone-secreting tumors or somatotroph adenomas.

Growth Hormone Secreting Pituitary Adenoma: Signs and Symptoms

Growth hormone-secreting adenomas, also known as somatotroph adenomas, are a type of pituitary tumor that produces excess growth hormone (GH). The effects of these tumors can vary depending on age. In children and teens, high GH levels can stimulate the growth of nearly all bones in the body, resulting in gigantism.

In adults, these adenomas are a common cause of acromegaly, a rare but serious condition that results from too much growth hormone. The symptoms of acromegaly include:

• Being very tall
• Enlarged face and hands
• Changes to the face may cause the brow bone and lower jawbone to protrude
• Other signs of acromegaly, such as fatigue, loss of muscle mass, and enlarged hands or feet

In children and teens, high GH levels can also lead to other symptoms, including:

• Rapid growth of bones and muscles
• Joint pain and stiffness
• Sleep apnea
• Headaches

It's essential to note that these symptoms can be similar to those caused by other conditions, so a proper diagnosis by a healthcare professional is crucial.

References:

• [2] Growth hormone-secreting adenomas make excess growth hormone (also known as somatotropin) and make up about 2 in 10 pituitary tumors.
• [7] GH-secreting adenomas are accompanied by high serum GH and insulin-like growth factor I (IGF-I) levels and signs and symptoms of acromegaly or gigantism.
• [9] A pituitary adenoma that increases the release of growth hormone in a child can cause a condition known as gigantism.

Diagnostic Tests for Growth Hormone Secreting Pituitary Adenoma

Growth hormone (GH) secreting pituitary adenomas are diagnosed using a combination of blood tests and imaging studies. Here are some of the diagnostic tests used to diagnose this condition:

• Blood tests: Blood tests can detect abnormal levels of growth hormone (GH) in the body. These tests can be done at any time, but they may not accurately reflect GH levels if taken after exercise or eating.
• Late-night salivary cortisol test: This is a screening test that measures the level of cortisol in saliva collected during sleep. Elevated cortisol levels can indicate an overproduction of growth hormone.
• Oral glucose tolerance test (OGTT): This test involves consuming a sugary drink and then measuring GH levels after 1-2 hours. A positive result indicates failure of GH to decrease, which is characteristic of acromegaly.
• Growth hormone suppression test: This test measures the level of GH in response to a glucose load or other stimuli. Failure of GH to suppress indicates an overproduction of growth hormone.

Imaging Studies

In addition to blood tests, imaging studies are also used to diagnose pituitary adenomas. These include:

• MRI scans: Magnetic Resonance Imaging (MRI) scans can help identify the size and location of a pituitary tumor.
• CT scans: Computed Tomography (CT) scans can also be used to visualize the pituitary gland and surrounding structures.

Other Tests

Other tests may be performed to rule out other conditions or to assess the impact of the adenoma on other bodily systems. These include:

• Vision tests: To assess any visual disturbances caused by a large tumor pressing on the optic nerves.
• Urine tests: To detect abnormal hormone levels in urine.

References

1. [7] - NYU Langone doctors diagnose pituitary tumors with blood and vision tests and MRI scans.
2. [8] - The diagnostic process for pituitary adenomas depends on what kind of adenoma you have and if it's causing symptoms or not.
3. [10] - The oral glucose tolerance test is the definitive test for the diagnosis of acromegaly; a positive result is the failure of GH to decrease to < 1 ng/mL after glucose ingestion.
4. [9] - Measurement of a late-night salivary cortisol level is the best screening test but petrosal sinus sampling for ACTH may be necessary to confirm the diagnosis.

Treatment Options for Growth Hormone Secreting Pituitary Adenomas

Growth hormone-secreting pituitary adenomas can be treated with various medications, which aim to reduce the production of excess growth hormone. Here are some treatment options:

• Somatostatin analogs: These medications, such as Lanreotide and Octreotide, help prevent the pituitary tumor from releasing excess growth hormone into the bloodstream. They can also decrease the size of the tumor [5].
• Pegvisomant (Somavert): This medication blocks the effect of too much growth hormone on the body by blocking the growth hormone receptor. It is taken as a shot every day [6].
• Cabergoline: This dopamine agonist can normalize insulin-like growth factor 1 (IGF-1) levels in approximately 37% of patients [4].

These medications are often used to treat growth hormone-secreting pituitary adenomas, especially when surgery is not an option or as a complement to surgical treatment. It's essential to consult with a healthcare professional to determine the best course of treatment for individual cases.

References:

[4] Cabergoline, the most efficacious DA, normalizes IGF-I in approximately 37% of patients, whereas the long-acting SST analogs, Octreotide LAR and Lanreotide SR, ...

[5] Somatostatin analog drugs decrease growth hormone production and may decrease the size of the tumor.

[6] Pegvisomant (Somavert). This medication blocks the effect of too much growth hormone on the body. It's taken as a shot every day.

The differential diagnosis of growth hormone-secreting pituitary adenomas involves distinguishing them from other conditions that may cause excessive growth hormone secretion.

Causes of Excessive Growth Hormone Secretion

• Somatotropinomas: These are the most common type of growth hormone-secreting adenomas, accounting for approximately 90% of cases [6].
• Diseases with increased growth hormone secretion: These include conditions such as acromegaly, gigantism, and certain types of tumors that produce growth hormone [9].

Diagnostic Approaches

To diagnose growth hormone-secreting pituitary adenomas, healthcare providers use a combination of clinical evaluation, laboratory tests, and imaging studies. The following approaches are commonly used:

• Clinical evaluation: Patients with suspected growth hormone-secreting adenomas undergo a thorough medical history and physical examination to assess for signs and symptoms of excessive growth hormone secretion [10].
• Laboratory tests: Blood tests are performed to measure levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-I), which can help confirm the diagnosis [6].
• Imaging studies: Imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT) scans may be used to visualize the pituitary gland and surrounding structures [11].

Key Points

• Growth hormone-secreting adenomas are a common cause of acromegaly in adults.
• The differential diagnosis of growth hormone excess includes somatotropinomas and diseases with increased secretion of growth hormone.
• A combination of clinical evaluation, laboratory tests, and imaging studies is used to diagnose growth hormone-secreting pituitary adenomas.

References:

[6] Growth hormone–secreting adenomas are accompanied by high serum GH and IGF-I levels and signs and symptoms of acromegaly or gigantism. Overall, these adenomas ... (Search Result 6) [9] The differential diagnosis of growth hormone (GH) excess includes somatotropinomas and diseases in which increased secretion of growth hormone– ... (Search Result 9) [10] Most patients with pituitary adenomas present with signs and symptoms of hormone hypersecretion (eg, hyperprolactinemia, growth hormone [GH] excess, or hypercortisolism). However, 25 to 35 percent of pituitary adenomas are clinically nonfunctioning or "silent"; 70 to 90 percent of these are gonadotroph adenomas, making them the most common type ... (Search Result 10) [11] Pituitary adenomas are tumors of the anterior pituitary. Most pituitary tumors are slow-growing and benign. They are classified based on size or cell of origin. Pituitary adenoma can be described as microadenoma, macroadenoma, and giant tumors based on size. Microadenoma is a tumor less than 10 mm, while macroadenoma describes a tumor larger than 10mm. Giant pituitary tumors are bigger than 40 ... (Search Result 11)